1. Field of the Invention
The present invention relates to an air heating apparatus such as a fan heater, a warm air heater of forced circulation type, an air conditioner/heater, etc.
2. Description of the Prior Art
A conventional controlling device for an air heating apparatus has been generally constructed in a manner as indicated in FIG. 18, which will now be described hereinbelow. As shown in the drawing, a temperature setting part 101 is provided for a user to set the temperature inside the room (space to be heated). The temperature inside the room is detected by a room temperature detecting part 102. Outputs from the temperature setting part 101 and room temperature detecting part 102 are input to a burning controlling part 103, to thereby control the operation of a burner part 104 and a convection fan 105. The burner part 104 is constituted of an electromagnetic pump 106 which supplies fuel to a burner (not shown) and a burner fan 107 for feeding air to the burner. The convection fan 105 emits the air heated by the burner as the warm air.
The operation of the controlling device in the above-described structure will be discussed below. When the temperature detected by the room temperature detecting part 102 is considerably lower than the temperature set by the temperature setting part 101, the burning controlling part 103 instructs intensive burning to the burner part 104 and also drives the convection fan 105 with a high rotating frequency. As the room temperature becomes closer to the set temperature, the controlling part 103 weakens the burner part 104 and rotates the convection fan 105 with a lower frequency. In this manner, the room temperature is controlled to a set temperature.
The controlling device of the air heating apparatus of the prior art makes control of the burning level of the burner part 104 and the air flow of the convection fan 105 based on the room temperature alone, without taking into consideration the temperature at the wall surface or floor surface of the space to be heated or the presence/absence of radiant heat like solar heat, etc. Therefore, the room is prone to be too hot or too cold to be comfortable.
Moreover, for making control of the burning level and air flow as mentioned above, the controlling device of the conventional air heating apparatus controls the temperature detected by the room temperature detecting part 102 to be equal to a set temperature of the temperature setting part 101. Therefore, it is difficult to realize the neutral state of thermal balance, that is, a too hot nor too cold state. The conventional controlling device cannot fill the change in the environmental condition.
A great demand has recently arising from the above-described background for an air heating apparatus capable of controlling heating in the balanced state.